Slides in this set

Slide 1

Slide 2

Homeostasis Homeostasis ­ the maintenance of a steady internal state in the body almost regardless of changes in either the external or the internal conditions. Changes in the body are detected by a sensor (receptor). This send a message to an effector which either works to reverse the change or increase it.…read more

Slide 3

Feedback systems Negative: A change in conditions is registered by receptors. Effectors are stimulated to restore the equilibrium. If the concentration goes up, the effectors bring it down again. Positive: Effectors work to increase the effect which has triggered the response. Communication may be by hormones or nerve impulses. There is often a small overshoot or undershoot as a feedback system corrects.…read more

Slide 4

Normal level Fall to a Rise to a higher lower level level Receptor ·If communication is Receptor Detects change hormonal, the Detects change effectors are theCommunication by: various target of the Communication by:1.Hormones hormones 1.Hormones2.Nervous system via ·If communication is 2.Nervous system viacoordination centre nervous, the effectors coordination centre are muscles or glands Effector Effector Carries out response Carries out response which brings out which brings out corrective change corrective change Rise to normal Fall to normal level level Normal level…read more

Slide 5

Changing cardiac outputCardiac output = cardiac volume x heart rate (dm3) (beats min-1) The volume of blood pumped The number of heart at each heartbeat beats per minute The cardiac volume can increase by more efficient contraction of the ventricles.…read more

Slide 6

Effect of Exercise When a fit athlete anticipates exercise: The heart rate begins to increase before exercise begins. The cardiac volume increases more slowly. Cardiac output increases.…read more